The clang compiler now reimplements and re-checks the c_std and cpp_std
options in order to use them for objc as well, but it didn't
consistently support the same options. First it completely excluded all
the gnu ones, and then it added a handful of them but not for C++.
Be fully consistent -- or at least as consistent as we can be, given a
minimally working fix. (The C/C++ compiler mixin actually gates
different stds depending on detected clang version, we do not do that
here.)
Fixes regression in c54dd63547
Fixes incomplete fix from #8766 (which didn't fix objcpp at all)
Fixes#9237
Allow using the links method to test that the C++ driver (e.g. g++) can be used to
link C objects. One usecase is that the C compiler's libsanitizer might not be
compatible with the one included by the C++ driver.
This is theoretically backwards-incompatible, but it should be treated as a
bugfix in my opinion. There is no way in Meson to compile a .c file with the
C++ driver as part of a build target, therefore there would be no reason to
do something like meson.get_compiler(meson.get_compiler('cpp').links(files('main.c')).
Fixes: #7703
In some cases, link tests would like to use objects provided by a compiler
for a different language, for example linking a C object file with a C++
compiler. This kind of scenario is what link_language is for, but it is
impossible to test that it works with a linker test.
This patch implements the required support in the Compiler class. The
source code compiler is passed to the Compiler.links method as an
argument.
* compilers: improve docstring to `get_compiler_check_args()`
There was an incomplete list, which wasn't useful as it now takes an
enum anyway. Also add a new entry to the list of reasons to use this
function.
* clang: Add -Werror=implicit-function-declarations to check_args
Unlike GCC, clang warns but doesn't error when an implicit function
declaration happens. This means in checks like
`compiler.has_header_symbol('string.h', 'strlcat')` (on Linux, at least)
that GCC will fail, as there is no such function; clang will emit a
warning, but since it exists with a 0 status Meson interprets that as
success. To fix this, add `-Werror=implicit-function-declarations` to
clang's check arguments.
There seems to be something specific about functions that _may_ exist in
a header on a given system, as `cc.has_header_symbol('string.h',
'foobar')` will return false with clang, but `strlcat` will return true,
even though it's not defined. It is however, defined in some OSes, like
Solaris and the BSDs.
Fixes#9140
We have a lot of these. Some of them are harmless, if unidiomatic, such
as `if (condition)`, others are potentially dangerous `assert(...)`, as
`assert(condtion)` works as expected, but `assert(condition, message)`
will result in an assertion that never triggers, as what you're actually
asserting is `bool(tuple[2])`, which will always be true.
There are two changes here, one is to remove an `elif` that is
effectively an `else`, that helps the type checker and provides a small
speedup potentially. The second is a potentially unbound variable, that
currently isn't hit, but very much could be.
When mutable items are stored in an lru cache, changing the returned
items changes the cached items as well. Therefore we want to ensure that
we're not mutating them. Using the ImmutableListProtocol allows mypy to
find mutations and reject them. This doesn't solve the problem of
mutable values inside the values, so you could have to do things like:
```python
ImmutableListProtocol[ImmutableListProtocol[str]]
```
or equally hacky. It can also be used for input types and acts a bit
like C's const:
```python
def foo(arg: ImmutableListProtocol[str]) -> T.List[str]:
arg[1] = 'foo' # works while running, but mypy errors
```